data SEGMENT
    org 80h
    offset_address dw 2000h
    base_address dw 1000h
data ENDS
code SEGMENT
    assume ds:data, cs:code
start:
    mov ax, data
    mov ds, ax
    mov ax, [base_address]
    mov es, ax
    mov si, [offset_address]
    mov dx, [es:si]
    mov ax, 4ch
    int 21h
code ENDS
end start